What Am I Riddles

Question: When people cut me, I do not bleed. They use me, but then they leave. I die, but then revive. I change my appearance as time goes by. What am I?

Question: When you are born, all you have is me. And even though you're powerless, you are filled with glee. What am I?

Question: he is a king who's good at measuring stuff.

Question: I can't go left, I can't go right. I am forever stuck in a building over three stories high. What am I?

Question: What has teeth but can't bite?